SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8d4673c225ef8a383f3f44eb7d64f4af8a544555e013c93493ef3b6a66cf0dea' 
  AND token = 'Mnm6Q65ntVAdficFUyb0d9plsTO9y3K3A9bWjRFEPUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}